Field of the Invention
The embodiments disclosed herein relate to an encoder, a controller, and a method for processing data.
Discussion of the Background
Japanese Unexamined Patent Application Publication No. 2010-152595 discloses a motor control system that includes an encoder-equipped motor and an additional encoder mounted on the encoder-equipped motor. Based on outputs from the two encoders, the motor control system monitors the motor by checking whether there is an abnormality in the motor. Japanese Unexamined Patent Application Publication No. 2003-346273 discloses an encoder that includes a plurality of sensors mounted in the encoder. The encoder checks whether there is a contradiction between pieces of position information detected by the plurality of sensors. Then, the encoder adds the check result to data and sends the data to a controller or another device.
Japanese Patent No. 3370845 discloses an encoder that determines whether there is a data abnormality. When the encoder has determined that there is a data abnormality, the encoder sends an alarm to a controller in response to a request signal from the controller. Japanese Patent No. 5104523 discloses an encoder that includes a signal processing circuit that generates a first check code and a second check code. The first check code is used for cyclic redundancy check with respect to measurement information, and the second check code is used for overall check, with respect to the first check code and the measurement information. The encoder uses the first and second check codes to improve data reliability.